1. Field of the Invention
This invention relates to an abrasion-resistive high permeability magnetic alloy for a magnetic head and more specifically to a Fe-Al-Si type alloy having improved magnetic properties and to a method for effecting the heat-treatment of the alloy. Further, the present invention relates to a magnetic head usind said alloy.
2. Brief Description of the Prior Art
As materials for magnetic recording and playback heads in analog and digital magnetic recording, there have, to this date, been used primarily permalloy and sen-alloy as the materials of a metal type and Mn-Zn ferrite and Ni-Zn ferrite as the materials of a ferrite type. However, the former exhibits a problem in its abrasion resistivity while the latter has low saturation magnetic flux density and is not free from the problem of the occurrence of noise inherent to the ferrite.
An alloy consisting of 8-11 wt.% of Si,4-7 wt.% of Al and the balance of Fe is referred to as a 37 sen-alloy" and has excellent magnetic properties such as high permeability and high saturation magnetic flux density so that the material is believed to be a promising core material for a magnetic head. However, further improvement of this material in its abrasion resistivity is necessary in order to put the material into practical use. Many attempts have therfore been made heretofore to improve the abrasion resistivity of such materials by adding Ti, Ge, Zr, Cu, Nb, Ta, Ni, Cr, Co, W, Mo, Hf and rare earth elements to a Fe-Al-Si alloy as the principal component.
When the abrasion resistivity is improved by the addition of these elements, however, the magnetic property of the sen-alloy tends to be lowered. If a composition is selected which will prevent degradation of the magnetic property on the contrary, remarkable improvement in the abrasion resistivity can not be expected. Hence, the above-mentioned attempts are not yet entirely satisfactory.
The following references are cited to show the state of the art;
(1) Japanese Patent Laid-Open No. 110,925/1975 PA1 (2) Japanese Patent Laid-Open No. 56,397/1977 PA1 (3) Japanese Patent Laid-Open No. 21,031/1978